<template>
  <div id="bue">
    <div class="box"></div>
  </div>
</template>
<script>
export default {
  name: "bue"
};
</script>
<style scoped>
.box {
  width: 100%;
  height: 50px;
  background: red;
  position: fixed;
  top: 0;
  z-index: 99;
}
</style>